JP2016532261A - Solid composite fluoropolymer separator - Google Patents

Abstract

The present invention is a method for producing a solid composite separator, comprising the following steps: (i) —repeating one or more main chains, derived from at least one fluorinated monomer [monomer (F)] From the main chain containing the unit, and the —O—Rx and —C (O) O—RX groups, wherein RX is a hydrogen atom or a C1-C5 hydrocarbon group containing at least one hydroxyl group. At least one fluoropolymer [polymer (F)] comprising one or more side functional groups selected from the group consisting of:-optionally, formula (I): X4-mAYm, wherein X is 1 A hydrocarbon group optionally containing one or more functional groups, m is an integer from 1 to 4, A is a metal selected from the group consisting of Si, Ti and Zr, and Y is Alkoxy groups, acyloxy groups and At least one metal compound [compound (M)], which is a hydrolyzable group selected from the group consisting of droxyl groups), at least one inorganic filler [filler (I)], and liquid medium [medium And (ii) a step of obtaining a liquid composition [composition (L)], preferably comprising them; (ii) a porous substrate layer made of one or more sets of polymer fibers [substrate ( (Iii) applying the composition (L) onto the substrate (P), thereby obtaining a wet substrate (P) [substrate (P-W)]; (Iv) drying and then optionally curing the substrate (P-W) obtained in step (iii), thereby obtaining a solid composite separator; (v) optionally, A step of subjecting the solid composite separator obtained in (iv) to compression; It said method comprising. The invention also relates to a solid composite separator obtainable by said method and the use of the solid composite separator in an electrochemical device. [Selection figure] None

Description

  This application claims priority to European Patent Application Publication No. 131800282.6 filed on August 12, 2013, the entire contents of which are incorporated herein by reference for all purposes. .

  The present invention relates to a method for producing a solid composite fluoropolymer separator, a solid composite fluoropolymer separator obtainable from said method, and the use of a solid composite fluoropolymer separator in an electrochemical device.

  Separators for use in electrochemical devices, particularly secondary batteries, primarily physically and electrically separate the negative electrode from the positive electrode of the electrochemical cell while allowing electrolyte ions to flow therethrough. To help.

  The separator must be chemically and electrochemically stable to the electrolyte and electrode material and must be mechanically strong to withstand the high tensions that occur during battery assembly operations.

  In addition, their structure and properties significantly affect battery performance, including energy density, power density, cycle life, and safety.

  Because of the high energy density and power density, the separator needs to be very thin and highly porous while still remaining mechanically strong.

  For battery safety, shutting down the battery when overheating occurs so that thermal runaway that causes physical contraction of the electrode, resulting in separator shrinkage or melting, and the resulting internal short circuit can be avoided. It must be possible.

  Also, small thickness separators are required for high energy density and power density. However, this adversely affects the resulting mechanical strength of the separator and battery safety.

  Inorganic composite membranes have been widely used as separators for electrochemical devices including secondary batteries, particularly lithium ion batteries.

  Various inorganic filler materials have long been used to produce inorganic composite membranes in which inorganic particles are distributed throughout the polymer binder matrix.

  Inorganic composite membranes provide excellent wettability by electrolyte, good thermal stability and zero dimensional shrinkage at high temperatures, but they are usually sufficiently mechanically strong to withstand handling in cell winding and assembly. Absent.

  In particular, a separator used in a wound electrochemical cell requires high mixed penetration strength to avoid penetration of electrode material through the separator. A short circuit occurs when particulate material from the electrode penetrates the separator.

  In many cases, the inorganic composite membrane contains a very high content of inorganic filler material. In some cases, the inorganic composite membrane so obtained exhibits insufficient mechanical strength.

  Accordingly, one particular challenge has been to provide a multilayer composite membrane with an acceptable thickness that is suitably used as a separator for electrochemical devices.

  Multilayer composite membranes can be obtained using a multi-step coating process. However, the multi-step process disadvantageously increases processing costs.

  Thus, an alternative method for manufacturing a solid composite separator, and thus having a high porosity, and thus high ionic conductivity, suitable for use as an electrochemical device separator, while in its assembly and / or operation There remains a need in the art for solid composite separators that maintain exceptional thermomechanical properties.

  It has now surprisingly been found that the solid composite separator of the present invention advantageously has enhanced thermomechanical properties for proper use in an electrochemical cell.

In a first example, the present invention is a method for producing a solid composite separator comprising the following steps:
(I)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)],
-Optionally, formula (I):
X _4-m AY _m
Wherein X is a hydrocarbon group optionally containing one or more functional groups, m is an integer from 1 to 4, and A is a metal selected from the group consisting of Si, Ti and Zr. And Y is a hydrolyzable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group)
At least one metal compound [compound (M)],
-At least one inorganic filler [filler (I)], and-liquid medium [medium (L)].
Obtaining a liquid composition [composition (L)], preferably comprising them;
(Ii) obtaining a porous substrate layer [substrate (P)] made of one or more sets of polymer fibers;
(Iii) applying the composition (L) onto the substrate (P), thereby obtaining a wet substrate (P) [substrate (P-W)];
(Iv) drying the substrate (P-W) obtained in step (iii) and then optionally curing to obtain a solid composite separator;
(V) optionally, subjecting the solid composite separator obtained in step (iv) to compression.

The reaction for obtaining a polymer (FG) is shown. A polymer (F-H) is shown.

According to a first embodiment of the method of the present invention, the present invention is a method for producing a solid composite solid separator comprising the following steps:
(I-1)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)],
-At least one inorganic filler [filler (I)], and-liquid medium [medium (L)].
Obtaining a liquid composition [(composition (L)], preferably comprising them;
(Ii-1) obtaining a porous base material layer [base material (P)] made of one or more sets of polymer fibers;
(Iii-1) applying the composition (L) onto the substrate (P), thereby obtaining a wet substrate (P) [substrate (P-W)];
(Iv-1) drying the substrate (PW) obtained in step (iii-1) and then optionally curing to thereby obtain a solid composite separator;
(V-1) optionally, subjecting the solid composite separator obtained in step (iv-1) to compression.

According to a second embodiment of the method of the present invention, the present invention is a method for producing a solid composite separator comprising the following steps:
(I-2)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)],
-Formula (I):
X _4-m AY _m
Wherein X is a hydrocarbon group optionally containing one or more functional groups, m is an integer from 1 to 4, and A is selected from the group consisting of Si, Ti and Zr. And Y is a hydrolyzable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group)
At least one metal compound [compound (M)],
-At least one inorganic filler [filler (I)], and-liquid medium [medium (L)].
Obtaining a liquid composition [composition (L)], preferably comprising them;
(Ii-2) obtaining a porous base material layer [base material (P)] made of one or more sets of polymer fibers;
(Iii-2) reacting at least a part of the side functional group of the polymer (F) with at least a part of the hydrolyzable group Y of the compound (M), thereby forming one or more main chains. A main chain containing a repeating unit derived from at least one fluorinated monomer [monomer (F)], and a formula -Y _m-1 -AX _4-m (wherein m, Y, A and X are A liquid composition [composition (L1)] comprising at least one grafted fluoropolymer [polymer (FG)] comprising one or more pendant groups (having the same meaning as defined above) Obtaining a step;
(Iv-2) Fluoropolymer domain consisting of chains that can be obtained by at least partial hydrolysis and / or polycondensation of the composition (L1) obtained in step (iii-2), thereby obtaining the polymer (FG) And a liquid composition comprising at least one fluoropolymer hybrid organic / inorganic composite [polymer (FH)] comprising, preferably consisting of, inorganic domains consisting of residues obtainable by compound (M) [ Obtaining a composition (L2)];
(V-2) The composition (L2) obtained in step (iv-2) is applied onto the substrate (P), whereby the wet substrate (P) [substrate (P-W)]. Obtaining
(Vi-2) drying the substrate (PW) obtained in step (V-2) and then optionally curing it to obtain a solid composite separator;
(Vii-2) optionally, subjecting the solid composite separator obtained in step (vi-2) to compression.

  In a second example, the present invention relates to a solid composite separator obtainable by the method of the present invention.

Therefore, the present invention also provides
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)],
-Optionally, at least one fluoropolymer comprising, preferably consisting of a fluoropolymer domain consisting of chains obtainable by polymer (FG) and an inorganic domain consisting of residues obtainable by compound (M) Polymer hybrid organic / inorganic composite [polymer (F-H)], and-at least one inorganic filler [filler (I)]
At least one layer [layer (1)] made from a solid composition [composition (S)] comprising: and adhered to at least one surface of said layer (1),
(2) The present invention relates to a solid composite separator including a porous base material layer [base material (P)] [layer (2)] made of one or more sets of polymer fibers.

  By the term “solid composite separator” is intended herein to mean a composite separator in the solid state at 20 ° C. under atmospheric pressure.

  By the term “solid composition [composition (S)]” is intended herein to mean a composition in the solid state at 20 ° C. under atmospheric pressure.

  The solid composite separator obtainable by the method of the present invention is a single composite in which at least one surface of at least one layer (1) made from the composition (S) is bonded to the substrate (P). It is understood to be an aggregate.

  It has been found that the solid composite separator of the present invention advantageously has a low dimensional shrinkage value over a wide range of temperatures and therefore cannot curl at the ends when unwound during assembly of the electrochemical cell.

  Also, the solid composite separator of the present invention advantageously has a high mixed penetration strength value regardless of its thickness, and therefore penetration through the separator of electrode material during assembly and winding of the electrochemical cell. It was found that it can withstand.

  Furthermore, it has been found that the solid composite separator of the present invention advantageously has excellent mechanical strength over a wide range of temperatures.

The solid composite separator obtainable by the first embodiment of the method of the present invention is typically (1)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer “polymer (F)”, and at least one inorganic filler [filler (I)]
At least one layer [layer (1)] made from a solid composition [composition (S)] comprising: and adhered to at least one surface of said layer (1),
(2) A porous base material layer [base material (P)] [layer (2)] made of one or more sets of polymer fibers.

The solid composite separator obtainable by the second embodiment of the method of the present invention is typically (1)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)],
At least one fluoropolymer hybrid organic comprising, preferably consisting of, a fluoropolymer domain consisting of chains obtainable by polymer (FG) and an inorganic domain consisting of residues obtainable by compound (M) / Inorganic composite [polymer (F-H)], and-at least one inorganic filler [filler (I)]
At least one layer [layer (1)] made from a solid composition [composition (S)] comprising: and adhered to at least one surface of said layer (1),
(2) A porous base material layer [base material (P)] [layer (2)] made of one or more sets of polymer fibers.

  In a third example, the present invention relates to the use of the solid composite separator of the present invention in an electrochemical device.

  Non-limiting examples of suitable electrochemical devices include secondary batteries, especially alkaline or alkaline earth secondary batteries such as lithium ion batteries, and capacitors, especially lithium ion capacitors.

  The solid composite separator of the present invention generally has a porosity of advantageously at least 5%, preferably at least 10%, more preferably at least 20%, and advantageously at most 90%, preferably at most 80%. Have.

  The determination of the porosity can be performed by any appropriate method.

  The solid composite separator of the present invention has a thickness generally comprised between 10 μm and 200 μm, preferably between 10 μm and 100 μm, more preferably between 15 μm and 50 μm.

  The thickness can be determined by any suitable method. The thickness is preferably determined according to the procedure of the ISO 4593 standard.

  In a fourth example, the present invention relates to the use of the composite solid separator of the present invention in a secondary battery.

Accordingly, the present invention further provides
A solid composite separator according to the invention,
-Negative electrode,
-A positive electrode; and-a secondary battery comprising a charge retention medium and an electrolyte comprising at least one metal salt.

  The solid composite separator of the present invention is typically located between the positive electrode and the negative electrode of the secondary battery.

The polymer (F) typically comprises at least one fluorinated monomer [monomer (F)], —O—R _x and —C (O) O—R _X groups, wherein R _X is hydrogen Or at least one hydrogenated monomer comprising one or more functional groups selected from the group consisting of C _{1 to} C ₅ hydrocarbon groups comprising at least one hydroxyl group [monomer (H _f )] , And optionally, can be obtained by polymerization of at least one hydrogenated monomer [monomer (H)] different from the monomer (H _f ).

  By the term “fluorinated monomer [monomer (F)]” is intended herein to mean an ethylenically unsaturated monomer containing at least one fluorine atom.

  By the term “hydrogenated monomer” is intended herein to mean an ethylenically unsaturated monomer containing at least one hydrogen atom and no fluorine atoms.

  The term “at least one fluorinated monomer” is understood to mean that the polymer (F) may comprise repeating units derived from one or more fluorinated monomers. In the rest of the text, the expression “fluorinated monomer” is used in the plural and singular form for the purposes of the present invention, ie they are one or more fluorines as defined above. It is understood to mean both fluorinated monomers.

  The term “at least one hydrogenated monomer” is understood to mean that the polymer (F) may comprise repeating units derived from one or more hydrogenated monomers. In the remainder of the text, the expression “hydrogenated monomer” is used in the plural and singular form for the purposes of the present invention, ie they are one or more hydrogens as defined above. It is understood to mean both fluorinated monomers.

The polymer (F) preferably contains at least 0.01 mol%, more preferably at least 0.05 mol%, even more preferably repeating units derived from at least one monomer (H _f ) as defined above. Preferably it contains at least 0.1 mol%.

The polymer (F) preferably comprises at least 20 mol%, more preferably at most 15 mol%, even more preferably, repeating units derived from at least one monomer (H _f ) as defined above. It contains at most 10 mol%, most preferably at most 3 mol%.

The determination of the average mole percent of monomer (H _f ) repeat units in polymer (F) can be made by any suitable method. In particular, acid-base titration methods (e.g. well suited for determination of acrylic acid content), NMR methods (suitable for quantification of monomers containing aliphatic hydrogen in the side chain ( _Hf )), polymers ( F) There may be mentioned a weight equilibrium method based on the total feed monomer (H _f ) and unreacted residual monomer (H _f ) during production.

The monomer (H _f ) is typically a (meth) acrylic monomer of formula (II) or a vinyl ether monomer of formula (III):
Wherein each of R ₁ , R ₂ and R ₃ is equal to or different from each other and is independently a hydrogen atom or a C ₁ -C ₃ hydrocarbon group, and R _X is a hydrogen atom or at least one a _C 1 -C ₅ hydrocarbon moiety comprising a hydroxyl group)
Selected from the group consisting of

The monomer (H _f ) preferably follows the formula (II) as defined above.

The monomer (H _f ) is more preferably the formula (II-A):
Wherein R ′ ₁ , R ′ ₂ and R ′ ₃ are hydrogen atoms and R ′ _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon moiety containing at least one hydroxyl group.
Follow.

Non-limiting examples of monomers (H _f ) include, among others, acrylic acid, methacrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxyethylhexyl (meth) acrylate.

The monomer (H _f ) is even more preferably:
− Formula:
Hydroxyethyl acrylate (HEA),
2-hydroxypropyl acrylate (HPA)
− Formula:
Acrylic acid (AA) of
-And their mixtures.

  The polymer (F) may be amorphous or semicrystalline.

  The term “amorphous” means a polymer (F) having a heat of fusion of less than 5 J / g, preferably less than 3 J / g, more preferably less than 2 J / g, measured according to ASTM D-3418-08. Is intended by this specification.

  The term “semicrystalline” means a polymer (F) having a heat of fusion of 10 to 90 J / g, preferably 30 to 60 J / g, more preferably 35 to 55 J / g, measured according to ASTM D3418-08. Is intended by the present specification.

  The polymer (F) is preferably semicrystalline.

Non-limiting examples of suitable monomers (F) include in particular:
- C ₃ -C ₈ perfluoroolefins, for example, tetrafluoroethylene and hexafluoropropene;
- C ₂ -C ₈ hydrogenated fluoroolefins, such as vinylidene fluoride, vinyl fluoride, 1,2-difluoroethylene and trifluoroethylene;
- _{(wherein, R f0 is,} C 1 -C ₆ perfluoroalkyl) formula _CH 2 = _{CH-R f0} perfluoroalkylethylene according to;
- chloro - and / or bromo - and / or iodo _-C 2 -C ₆ fluoroolefins, for example chlorotrifluoroethylene;
(Per) fluoroalkyl according to the formula CF ₂ = CFOR _f1 , where R _f1 is a C ₁ -C ₆ fluoro- or perfluoroalkyl, eg CF ₃ , C ₂ F ₅ , C ₃ F ₇ Vinyl ether;
- a CF ₂ = CFOX ₀ (per) - oxy alkyl vinyl ethers (wherein, _{X 0 is,} C with C 1 _{-C 12} alkyl _group, C 1 _{-C 12} oxyalkyl group, or one or more ether groups _{1 to} C ₁₂ (per) fluorooxyalkyl groups, such as perfluoro-2-propoxy-propyl groups);
- wherein _{CF 2} = CFOCF 2 OR _{f2 (wherein, R f2 is} fluoro C 1 -C ₆ - or perfluoroalkyl group, for example _{CF 3, C 2 F 5,} C 3 F 7 or one or more ether (Per) fluoroalkyl vinyl ethers according to C ₁ -C ₆ (per) fluorooxyalkyl groups having a group, for example —C ₂ F ₅ —O—CF ₃ ;
- wherein _CF 2 = CFOY ₀ (wherein, _{Y 0 is, C 1} having a C 1 _{-C 12} alkyl or (per) fluoroalkyl _group, C 1 _{-C 12} oxyalkyl group or one or more ether groups, -C 12 _(per) fluoro oxyalkyl group, and Y ₀ is the acid, the functional according to containing a carboxylic acid or sulfonic acid group) in the form of an acid halide or salt (per) - oxy alkyl ether;
Fluorodioxole, in particular perfluorodioxole, is included.

  Monomer (H) is typically selected from the group consisting of non-functional monomers (H). The non-functional monomer (H) usually does not contain one or more functional groups.

  Non-limiting examples of suitable monomers (H) include styrene monomers such as ethylene, propylene and isobutylene, and styrene and p-methylstyrene, among others.

  The polymer (F) preferably contains more than 25 mol%, preferably more than 30 mol%, more preferably more than 40 mol% of repeating units derived from at least one monomer (F).

The polymer (F) preferably contains more than 1 mol%, preferably more than 5 mol%, more preferably more than 10 mol% of repeating units derived from at least one monomer (H) different from the monomer (H _f ). Including.

  Monomer (F) can further comprise one or more other halogen atoms (Cl, Br, I). If the fluorinated monomer does not contain a hydrogen atom, it is referred to as a per (halo) fluoromonomer. If monomer (F) contains at least one hydrogen atom, it is referred to as a hydrogen-containing fluorinated monomer.

When the monomer (F) is a hydrogen-containing fluorinated monomer, such as vinylidene fluoride, trifluoroethylene, vinyl fluoride, etc., the polymer (F) comprises at least one monomer (H _In addition to the repeating unit derived from _f ), it may be a polymer comprising repeating units derived solely from the hydrogen-containing fluorinated monomer, or it may be at least one monomer (H _f ) as defined above Or a polymer comprising repeating units derived from the hydrogen-containing fluorinated monomer and at least one other monomer.

When the monomer (F) is a per (halo) fluoromonomer, such as tetrafluoroethylene, chlorotrifluoroethylene, hexafluoroethylene, perfluoroalkyl vinyl ether, etc., the polymer (F) is as defined above It is a polymer comprising a repeating unit derived from at least one monomer (H _f ), the per (halo) fluoromonomer, and at least one other monomer (H) different from (H _f ).

  Preferred polymer (F) has at least one monomer having one or more main chains and selected from the group consisting of vinylidene fluoride (VDF), tetrafluoroethylene (TFE) and chlorotrifluoroethylene (CTFE). The main chain containing the repeating unit derived from (F) is included.

The polymer (F) is more preferably-vinylidene fluoride (VDF), at least one (H _f ) as defined above and optionally one or more monomers (F) different from VDF. polymers comprising repeating units derived from (F-1), and - is selected from at least one monomer as defined above _(H f), tetrafluoroethylene (TFE) and chlorotrifluoroethylene (CTFE) At least one per (halo) fluoromonomer and at least one monomer (H) selected from ethylene, propylene and isobutylene (optionally typically TFE and / or CTFE and said monomer (H) One or more additional in an amount of 0.01 mol% to 30 mol%, based on the total amount of It is selected from the group consisting of a polymer (F-2) containing a repeating unit derived from a containing monomer).

The polymer (F-1) is preferably (a ′) at least 60 mol%, preferably at least 75 mol%, more preferably at least 85 mol% vinylidene fluoride (VDF);
(B ′) optionally 0.1 mol% to 15 mol%, preferably 0.1 mol% to 12 mol%, more preferably 0.1 mol% to 10 mol% of vinyl fluoride (VF ₁ ), Chlorotrifluoroethylene (CTFE), hexafluoropropene (HFP), tetrafluoroethylene (TFE), trifluoroethylene (TrFE), at least one monomer (FVE) selected from perfluoromethyl vinyl ether (PMVE) And (c) 0.01 mol% to 20 mol%, preferably 0.05 mol% to 18 mol%, more preferably 0.1 mol% to 10 mol%, as defined above, II) at least one monomer (H _f )
including.

  In polymer (F-2) as defined above, the molar ratio of per (halo) fluoromonomer / monomer (H) is typically 30:70 to 70:30. In polymer (F-2) as defined above, monomer (H) is preferably ethylene, optionally in combination with other monomers (H).

  Polymer (F-2) in which the per (halo) fluoromonomer is primarily chlorotrifluoroethylene (CTFE) is identified below as an ECTFE copolymer; a polymer in which the per (halo) fluoromonomer is primarily tetrafluoroethylene (TFE) (F-2) is specified below as an ETFE copolymer.

The polymer (F-2) is preferably (a) 35 mol% to 65 mol%, preferably 45 mol% to 55 mol%, more preferably 48 mol% to 52 mol% ethylene (E);
(B) selected from the group consisting of 65 mol% to 35 mol%, preferably 55 mol% to 45 mol%, more preferably 52 mol% to 48 mol%, chlorotrifluoroethylene (CTFE) and tetrafluoroethylene. At least one per (halo) fluoromonomer;
(C) of the formula (II) as defined above from 0.01 mol% to 20 mol%, preferably from 0.05 mol% to 18 mol%, more preferably from 0.1 mol% to 10 mol% Contains at least one monomer (H _f ).

  Among the polymers (F-2), ECTFE polymer is preferable.

  The polymer (F) is even more preferably selected from the polymers (F-1) as defined above.

  The polymer (F) can typically be obtained by emulsion polymerization or suspension polymerization.

The metal compound of the formula X _4-m AY _m (I) can contain one or more functional groups on both the groups X and Y, preferably on at least one group X group.

  If the metal compound of formula (I) as defined above contains at least one functional group, it is called a functional metal compound; if neither group X nor group Y contains a functional group, The metal compound of formula (I) as defined in is referred to as a non-functional metal compound.

  Mixtures of one or more functional metal compounds and one or more non-functional compounds can be used in the method of the present invention. Otherwise, functional metal compounds or non-functional metal compounds can be used separately.

  The functional metal compound is preferably a polymer with functional groups (FH) in order to further modify the chemistry and properties of the polymer (FH) relative to the unmodified polymer (F) and the unmodified inorganic phase. Can give.

Compound (M) is preferably of the formula (IA):
R ′ _{4-m ′} E (OR ″) _{m ′} (IA)
Wherein m ′ is an integer from 1 to 4 and according to certain embodiments, E is a metal selected from the group consisting of Si, Ti and Zr, and R ′ And R ″ are equal to or different from each other and at each occurrence, and are independently selected from C _{1 to} C ₁₈ hydrocarbon groups optionally including one or more functional groups)
Follow.

  Non-limiting examples of functional groups include epoxy groups, carboxylic acid groups (its acid, ester, amide, anhydride, salt or halide form), sulfonic acid groups (its acid, ester, salt or halide form) ), Hydroxyl group, phosphate group (in the form of its acid, ester, salt or halide), thiol group, amine group, quaternary ammonium group, ethylenically unsaturated group (such as vinyl group), cyano group, Examples include urea groups, organosilane groups, and aromatic groups.

  For the purpose of producing a polymer (FH) capable of exhibiting a functional behavior with respect to hydrophilicity or ionic conductivity, the functional group of the metal compound of formula (I) is preferably a carboxylic acid group (its acid, ester, Amide, anhydride, salt or halide form), sulfonic acid group (in its acid, ester, salt or halide form), hydroxyl group, phosphate group (in its acid, ester, salt or halide form), Selected from among amine groups and quaternary ammonium groups; most preferred are carboxylic acid groups (in the form of their acids, esters, amides, anhydrides, salts or halides) and sulfonic acid groups (of their acids, esters) , In the form of salt or halide).

When compound (M) is a functional metal compound, it is more preferably of formula (IB):
R ^A _{4-m *} E ^* (OR ^B ) _{m *} (IB)
(Wherein m ^* is an integer from 2 to 3 and E ^* is a metal selected from the group consisting of Si, Ti and Zr, and R ^A is equal to each other and each occurrence, or Is a C _{1 to} C ₁₂ hydrocarbon group containing one or more functional groups; R ^B is equal to or different from each other and each occurrence and is a C _{1 to} C ₅ linear or branched alkyl group Preferably R ^B is methyl or ethyl).

Examples of functional metal compounds, in particular, vinyltriethoxysilane, vinyltrimethoxysilane, vinyl tris methoxyethoxy silane of the formula _{CH 2 = CHSi (OC 2 H} 4 OCH 3) 3, wherein:
2- (3,4-epoxycyclohexylethyltrimethoxysilane),
formula:
Glycidoxypropylmethyldiethoxysilane,
formula:
Glycidoxypropyltrimethoxysilane,
formula:
Of methacryloxypropyltrimethoxysilane,
formula:
Aminoethylaminepropylmethyldimethoxysilane,
formula:
_{H 2 NC 2 H 4 NHC 3} H 6 Si (OCH 3) 3
Aminoethylaminopropyltrimethoxysilane,
3-aminopropyltriethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-chloroisobutyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, n -(3-acryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, (3-acryloxypropyl) dimethylmethoxysilane, (3-acryloxypropyl) methyldichlorosilane, (3-acryloxypropyl) methyl Dimethoxysilane, 3- (n-allylamino) propyltrimethoxysilane, 2- (4-chlorosulfonylphenyl) ethyltrimethoxysilane, 2- (4-chlorosulfonylphenyl) ethyltrichlorosilane, cal Carboxyethyl silane triol and its sodium salt,
formula:
Of triethoxysilylpropyl maleamic acid,
Formula _{HOSO 2 -CH 2 CH 2 CH 2} -Si (OH) 3 3- (trihydroxysilyl) -1-propanesulfonic - sulfonic acid, N- (trimethoxysilylpropyl) ethylene - diamine triacetate and its sodium salt,
formula:
Of 3- (triethoxysilyl) propyl succinic anhydride,
Acetamidopropyltrimethoxysilane of formula H ₃ C—C (O) NH—CH ₂ CH ₂ CH ₂ —Si (OCH ₃ ) ₃ , formula Ti (A) _X (OR) _{Y where} A is an amine substitution An alkanolamine titanate of an alkoxy group, for example OCH ₂ CH ₂ NH ₂ , R is an alkyl group and x and y are integers such that x + y = 4).

  Examples of non-functional metal compounds are in particular trimethoxysilane, triethoxysilane, tetramethoxysilane, tetraethoxysilane (TEOS), tetramethyl titanate, tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate, tetra- n-butyl titanate, tetra-isobutyl titanate, tetra-tert-butyl titanate, tetra-n-pentyl titanate, tetra-n-hexyl titanate, tetraisooctyl titanate, tetra-n-lauryl titanate, tetraethyl zirconate, tetra-n -Propyl zirconate, tetraisopropyl zirconate, tetra-n-butyl zirconate, tetra-sec-butyl zirconate, tetra-tert-butyl zirconate, tetra- - a pentyl zirconate, tetra -tert- pentyl zirconate, tetra -tert- hexyl zirconate, tetra -n- heptyl zirconate, tetra -n- octyl zirconate, tetra -n- stearyl zirconate.

  The base material (P) is a porous base material layer [base material (P)] made of one or more sets of polymer fibers.

  For the purposes of the present invention, the term “fiber” is understood to mean a single continuous filament having a finite length.

  The polymer fibers typically have an average diameter comprised between 1 μm and 25 μm, preferably between 1 μm and 5 μm.

  The polymer fibers are preferably made from an electrically non-conductive polymer selected from the group consisting of polyesters such as polyethylene terephthalate, polyacrylonitrile, polyamides, polyimides, polyacrylates, polytetrafluoroethylene, and polyolefins.

  The polymer fibers may be assembled into a roving in which the polymer fibers as defined above are parallel to each other, or a yarn in which the polymer fibers as defined above are twisted together.

  The substrate (P) is advantageously a fabric made from one or more sets of polymer fibers.

  For the purposes of the present invention, by “fabric” is understood to mean a planar textile structure that can be obtained by interlacing one or more sets of polymer fibers, resulting in a large number of pores.

  The fabric may be a woven fabric made from one or more sets of polymer fibers, or a non-woven fabric made from one or more sets of polymer fibers.

  By “woven fabric” is meant a flat textile structure that can be obtained by crossing two or more sets of polymer fibers orthogonally to each other, thereby providing warp yarns extending in the machine direction of the fabric and weft yarns extending in the cross direction of the fabric. Is intended to be.

  By “nonwoven” is intended to mean a planar textile structure that can be obtained by randomly interlocking or bonding one or more sets of polymer fibers mechanically, thermally or chemically, resulting in a large number of pores. .

  The fabric may be a unidirectional fabric in which most polymer fibers extend in one direction.

  The fabric may also be a multidirectional fabric in which two or more sets of continuous fibers extend in different directions.

  The substrate (P) is preferably a nonwoven fabric made of one or more sets of polymer fibers, more preferably a nonwoven fabric made of polyethylene terephthalate fibers.

  The substrate (P) typically has a porosity of advantageously at least 5%, preferably at least 10%, more preferably at least 20%, and advantageously at most 90%, preferably at most 80%. Have

  The determination of porosity can be done by any suitable method.

  The substrate (P) typically has a thickness comprised between 10 μm and 200 μm, preferably between 10 μm and 100 μm, more preferably between 15 μm and 50 μm.

  The thickness determination can be made by any suitable method. The thickness is preferably determined according to the procedure of the ISO 4593 standard.

  For the purposes of the present invention, the term “inorganic” is used according to its ordinary meaning and is intended to mean an inorganic compound that does not contain carbon atoms and is therefore not considered an organic compound.

  The selection of the filler (I) is not particularly limited.

  Filler (I) is typically provided in the form of solid particles.

  The filler (I) particles generally have an average particle size of 0.001 μm to 200 μm, preferably 0.01 μm to 50 μm, more preferably 0.03 μm to 10 μm.

  In step (i) of the method of the present invention, composition (L) typically comprises at least one filler (I) different from compound (M), combined with polymer (F) and filler (I). It is contained in an amount of 60% to 95% by weight, more preferably 65% to 90% by weight, based on the weight.

  Among the fillers (I) suitable for use in the method of the present invention, mention may be made of inorganic oxides including mixed oxides, metal sulfates, metal carbonates, metal sulfides and the like.

  The classes of compounds that have given particularly good results in connection with this embodiment of the invention are in particular silicates, aluminum silicates and magnesium silicates, all of which are additional, such as sodium, potassium, iron or lithium These metals are optionally contained.

  These silicates, aluminum silicates and magnesium silicates, all optionally containing additional metals such as sodium, potassium, iron or lithium, are especially smectite clays of natural origin, for example, especially montmorillonite , Saconite, vermiculite, hectorite, saponite, nontronite. Alternatively, all optionally contain additional metals such as sodium, potassium, iron or lithium, silicates, aluminum silicates and magnesium silicates, such as fluorohectorite, hectorite, laponite, among others It can be selected from among synthetic clays.

  Filler (I) may also be selected from ion conductive inorganic filler materials.

  By the term “ionic conductivity” is intended herein to mean a material that allows electrolyte ions to flow therethrough.

Non-limiting examples of suitable ion conductive inorganic filler materials include, among others, lithium ceramics such as LiTaO ₃ —SrTiO ₃ , LiTi ₂ (PO ₄ ) ₃ —Li ₂ O and Li ₄ SiO ₄ —Li ₃ PO _4. Is included.

  Moreover, the filler (I) which has the reactive group with respect to a compound (M) on the surface may be used by the method of this invention.

  Among the surface reactive groups, mention may in particular be made of hydroxyl groups.

  While not being bound by this theory, the present applicant has determined that the reaction between at least a part of the hydrolyzable group Y of the compound (M) and at least a part of the surface reactive group of the filler (I) M) can occur simultaneously with the reaction of at least a portion of the hydrolyzable group Y with at least a portion of the side functional groups of the polymer (F), so that in subsequent hydrolysis and / or polycondensation, the polymer It is believed that the chemical bond between (F) and filler (I) appears to be achieved through an inorganic domain derived from compound (M).

  The filler (I) is preferably selected from inorganic oxides.

Non-limiting examples of suitable inorganic oxides, in _particular, include _{SiO 2, TiO 2, ZnO,} Al 2 O 3.

  By the term “liquid medium” is intended herein to mean a medium comprising one or more substances in a liquid state at 20 ° C. under atmospheric pressure.

  The medium (L) typically comprises, preferably consists of water, and optionally at least one organic solvent [solvent (S)].

  The medium (L) more preferably comprises water and at least one solvent (S), even more preferably consists thereof.

Non-limiting examples of suitable organic solvents (S) include, among others:
-Aliphatic, cycloaliphatic or aromatic ether oxides, more particularly diethyl oxide, dipropyl oxide, diisopropyl oxide, dibutyl oxide, methyl tertiobutyl ether, dipentyl oxide, diisopentyl oxide, ethylene glycol dimethyl ether , Ethylene glycol diethyl ether, ethylene glycol dibutyl ether benzyl oxide; dioxane, tetrahydrofuran (THF),
Glycol glycols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monomethyl ether Diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether;
-Glycol ether esters, such as ethylene glycol methyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate;
Alcohols such as methyl alcohol, ethyl alcohol, diacetone alcohol;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, isophorone, and chain or cyclic esters such as isopropyl acetate, n-butyl acetate, methyl acetoacetate, dimethyl phthalate, g-butyrolactone;
-Linear or cyclic amides such as N, N-diethylacetamide, N, N-dimethylacetamide, dimethylformamide and N-methyl-2-pyrrolidone; and-dimethyl sulfoxide.

  The solvent (S) is preferably selected from the group consisting of ketones.

  In step (i) of the process of the invention, the composition (L) advantageously comprises at least one filler (I) and optionally at least one compound (M) and at least one polymer. It can be obtained by adding to a composition comprising (F) and medium (L).

  In step (i) of the method of the invention, the composition (L) comprises at least one filler (I) and optionally at least one compound (M) and at least one polymer (F). It may be obtained by adding to an aqueous latex containing.

For the purposes of the present invention, “aqueous latex” refers to at least one fluorinated monomer [monomer (F)], —O—R _x and —C (O) O—R _X groups, wherein R _X Is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group) at least one hydrogenated monomer containing at least one functional group selected from the group consisting of (H _f )], and optionally at least one hydrogenated monomer different from monomer (H _f ) [monomer (H)], typically obtained by aqueous emulsion polymerization in an aqueous medium. The resulting aqueous latex is meant herein.

  Aqueous emulsion polymerization typically involves at least one surfactant [surfactant (S)], at least one initiator, and optionally at least one non-functional perfluoropolyether (PFPE) oil. Done in the presence of

  The aqueous latex obtainable by aqueous emulsion polymerization is preferably at least advantageously in the form of primary particles having an average primary particle size measured according to ISO 13321 comprised between 50 nm and 450 nm, preferably between 250 nm and 300 nm. Contains one polymer (F).

  For the purposes of the present invention, by “average primary particle size” is intended to mean the primary particles of the polymer (F) obtainable by aqueous emulsion polymerization. Thus, the primary particles of polymer (F) are recovered and adjusted for polymer (F) production, such as concentration and / or coagulation of aqueous polymer (F) latex and subsequent drying and homogenization to yield polymer (F) powder. It is intended to be distinguishable from agglomerates (ie, aggregates of primary particles) that may be obtained by the process.

  Accordingly, it is intended that the aqueous latex that can be obtained by aqueous emulsion polymerization is distinguishable from the aqueous slurry prepared by dispersing the polymer (F) powder in an aqueous medium. The average particle size of the polymer (F) powder dispersed in the aqueous slurry is typically higher than 1 μm as measured according to ISO 13321.

  The aqueous latex obtainable by aqueous emulsion polymerization advantageously has at least an average primary particle size comprised in the range from 50 nm to 450 nm, preferably from 250 nm to 300 nm, as measured according to ISO 13321, uniformly dispersed therein It has 1 type of primary particles of polymer (F).

  The aqueous emulsion polymerization process is typically carried out at a pressure comprised between 20 bar and 70 bar, preferably between 25 bar and 65 bar.

  The person skilled in the art selects the polymerization temperature, taking into account, among other things, the initiator used. The aqueous emulsion polymerization temperature is typically a temperature comprised between 60 ° C and 135 ° C, preferably between 90 ° C and 130 ° C.

The surfactant (S) is typically
-Hydrogenated surfactant [surfactant (H)],
-A fluorinated surfactant [surfactant (F)], and-selected from the group consisting of mixtures thereof.

  The surfactant (H) is preferably selected from the group consisting of a nonionic surfactant [surfactant (NS)].

  The surfactant (NS) is typically selected from the group consisting of fatty alcohol polyethers containing repeat units derived from ethylene oxide and / or propylene oxide.

  Surfactants (NS) generally have a cloud point of advantageously greater than 50 ° C., preferably greater than 55 ° C., measured according to EN 1890 standard (Method A: 1% by weight aqueous solution).

  Surfactant (NS) that gave very good results with the method of the present invention is MARLOSOL® TA, commercially available from Sasol Olefins and Surfactants GmbH, having a cloud point of 59 ° C. and an HLB of 13.3. 3090 nonionic surfactant.

  For the avoidance of doubt, the term “HLB” refers to the Water-Solubility Method, “The HLB System”, ICI Americas, Inc. , 1992 is meant a hydrophilic-lipophilic balance (HLB).

The surfactant (F) is preferably of the following formula (IV):
R _{f §} (X ⁻ ) _k (M ⁺ ) _k (IV)
(Where
-R _{f §} is selected from C _{4 to} C ₁₆ (per) fluoroalkyl chains, optionally comprising one or more catenary or non-catenary oxygen atoms, and (per) fluoropolyoxyalkyl chains;
- X ^- is, -COO ^-, -PO ₃ ^- is selected from, ^- and -SO ₃
-M ⁺ is selected from NH ₄ ⁺ and alkali metal ions;
-K is 1 or 2)
Follow.

Non-limiting examples of surfactants (F) suitable for aqueous emulsion polymerization processes include in particular:
(A ′) CF ₃ (CF ₂ ) _n0 COOM ′ (where n ₀ is an integer in the range of 4-10, preferably 5-7, preferably n ₀ is equal to 6 and M ′ is , NH ₄ , Na, Li or K, preferably NH ₄ )
(B ′) T— (C ₃ F ₆ O) _n1 (CFYO) _m1 CF ₂ COOM ″ [wherein T is a Cl atom or a formula C _x F _{2x + 1−x ′} Cl _{x ′} O (wherein x Is an integer in the range of 1 to 3 and x ′ is 0 or 1), n ₁ is an integer in the range of 1 to 6 and m ₁ is 0 or An integer in the range of 1 to 6, M ″ represents NH ₄ , Na, Li or K, and Y represents F or —CF ₃ ],
(C ′) F— (CF ₂ CF ₂ ) _{n 2} —CH ₂ —CH ₂ —X ^* O ₃ M ′ ″ (wherein X ^* is a phosphorus or sulfur atom, preferably X ^* is sulfur An atom, M ′ ″ represents NH ₄ , Na, Li or K, n ₂ is an integer in the range of 2-5, preferably n ₂ is equal to 3),
(D ′) A—R _bf —B bifunctional fluorinated surfactant [wherein A and B are equal to or different from each other and have the formula — (O) _p CFY ″ —COOM ^* (where M ^* Represents NH ₄ , Na, Li or K, preferably M ^* represents NH ₄ , Y ″ is F or —CF ₃ , and p is 0 or 1) , R _bf is a divalent (per) fluoroalkyl chain or (per) fluoropolyether chain such that the number average molecular weight of A—R _bf -B is in the range of 300-1800], and (e ′ ) Mixtures thereof.

  Preferred surfactants (F) follow the formula (a ') as described above.

  Although the choice of initiator is not particularly limited, it is understood that a water soluble initiator suitable for an aqueous emulsion polymerization process is selected from compounds that can initiate and / or accelerate the polymerization process.

  Inorganic radical initiators may be used and include, but are not limited to, persulfates such as sodium, potassium and ammonium persulfates, and permanganates such as potassium permanganate.

  Organic radical initiators may also be used and are not limited to the following: acetylcyclohexanesulfonyl peroxide; diacetyl peroxydicarbonate; dialkyl peroxydicarbonate such as diethyl peroxydicarbonate, dicyclohexyl peroxydicarbonate , Di-2-ethylhexyl peroxydicarbonate; tert-butyl perneodecanoate; 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile; tert-butyl perpivalate; dioctanoyl par Dilauroyl-peroxide; 2,2'-azobis (2,4-dimethylvaleronitrile); tert-butylazo-2-cyanobutane; dibenzoyl peroxide; tert-butyl-per-2ethylhexa Tert-butyl permaleate; 2,2′-azobis (isobutyronitrile); bis (tert-butylperoxy) cyclohexane; tert-butyl-peroxyisopropyl carbonate; tert-butyl peracetate; '-Bis (tert-butylperoxy) butane; dicumyl peroxide; di-tert-amyl peroxide; di-tert-butyl peroxide (DTBP); p-methane hydroperoxide; pinane hydroperoxide; Peroxides; and tert-butyl hydroperoxide.

Other suitable radical initiators include chlorocarbon and fluorocarbon acyl peroxides, such as trichloroacetyl peroxide, bis (perfluoro-2-propoxypropionyl) peroxide, [CF ₃ CF ₂ CF ₂ OCF (CF ₃ ) COO] ₂ , perfluoropropionyl peroxide, (CF ₃ CF ₂ CF ₂ COO) ₂ , (CF ₃ CF ₂ COO) ₂ , {(CF ₃ CF ₂ CF ₂ )-[CF (CF ₃ ) CF ₂ O _{] m -CF (CF 3) -COO} } 2 ( where a _{m = 0~8), [ClCF 2} (CF 2) n COO] 2, and _{[HCF 2 (CF 2) n} COO] 2 ( In which n = 0-8); perfluoroalkylazo compounds such as perfluoroazoisopropane, [(CF ₃ ) ₂ CFN =] ₂ ,
(Where
Is a linear or branched perfluorocarbon group having 1 to 8 carbons); a stable or hindered perfluoroalkane radical, such as a hexafluoropropylene trimer radical, [(CF ₃ ) ₂ CF] ₂ (CF ₂ CF ₂ ) C ^● Halogenated free radical initiators such as radicals and perfluoroalkanes are included.

  Redox systems containing at least two components that form a redox couple, such as dimethylaniline-benzoyl peroxide, diethylaniline-benzoyl peroxide and diphenylamine-benzoyl peroxide are also used as radical initiators to initiate the polymerization process. May be used.

  Of the inorganic radical initiators, ammonium persulfate is particularly preferred.

  Among organic radical initiators, for example, di-tert-butyl peroxide (DTBP), di-tert-butyl peroxyisopropyl carbonate, tert-butyl (2-ethyl-hexyl) peroxycarbonate, tert-butyl peroxy-3,3 Particularly preferred are peroxides having a self-accelerated decomposition temperature (SADT) higher than 50 ° C., such as 1,5-trimethylhexanoate.

  One or more initiators as defined above are added to the aqueous medium of the aqueous emulsion polymerization process, preferably in an amount ranging from 0.001% to 20% by weight, based on the weight of the aqueous medium. May be.

By “non-functional perfluoropolyether (PFPE) oil” is meant a perfluoropolyether (PFPE) oil comprising a (per) fluoropolyoxyalkylene chain [chain (R _f )] and a non-functional end group Is contemplated by this specification.

Non-functional end groups of PFPE oils are generally fluoro (halo) alkyl groups having 1 to 3 carbon atoms, including one or more halogen atoms different from fluorine or hydrogen atoms, such as CF ₃ —, C _{It is selected from 2} F _5- , C ₃ F _6- , ClCF ₂ CF (CF ₃ )-, CF ₃ CFClCF _2- , ClCF ₂ CF _2- , ClCF _2- .

  The non-functional PFPE oil has a number average molecular weight which is advantageously comprised between 400 and 3000, preferably between 600 and 1500.

The non-functional PFPE oil is more preferably
(1 ′) Solvay Solexis S. under the trade names GALDEN® and FOMBLIN®. p. A. Non-functional PFPE oils commercially available from, said PFPE oils generally have the following formula:
_{CF 3 - [(OCF 2 CF} 2) m - (OCF 2) n] -OCF 3
(M + n = 40-180; m / n = 0.5-2)
_{CF 3 - [(OCF (CF} 3) CF 2) p - (OCF 2) q] -OCF 3
(P + q = 8-45; p / q = 20-1000)
Comprising at least one PFPE oil according to any of the following:
(2 ′) Non-functional PFPE oil commercially available from Daikin under the trade name DENNUM®, said PFPE generally has the following formula:
Containing _{(CF 2 CF 2 CH 2 O} ) at least one PFPE according to _{j -CF 2 CF 3, - F-} (CF 2 CF 2 CF 2 O) n
(3 ′) Non-functional PFPE oil commercially available from Du Pont de Nemours under the trade name KRYTOX®, said PFPE generally having the following formula:
_{F- (CF (CF 3) CF} 2 O) n -CF 2 CF 3
n = 10-60
Comprising at least one low molecular weight fluorine end-capped homopolymer of hexafluoropropylene epoxide according to
Selected from the group consisting of

  The non-functional PFPE oil is even more preferably selected from those having the formula (1 ') as described above.

  The aqueous emulsion polymerization process as detailed above is typically performed in the presence of a chain transfer agent.

  Chain transfer agents are typically ketones, esters, ethers or aliphatic alcohols having 3 to 10 carbon atoms, such as, for example, acetone, ethyl acetate, diethyl ether, methyl-tert-butyl ether, isopropyl alcohol. Chloro (fluoro) carbons having 1 to 6 carbon atoms, optionally hydrogen, such as chloroform, trichlorofluoromethane; for example, bis (ethyl) carbonate, bis (isobutyl) carbonate As such, the alkyl is selected from those known in the polymerization of fluorinated monomers such as bis (alkyl) carbonates having 1 to 5 carbon atoms. The chain transfer agent may be fed to the aqueous medium at the beginning, continuously or in discrete amounts (stepwise) during the polymerization, with continuous or stepwise feeding being preferred.

  Aqueous emulsion polymerization processes as detailed above are described in the art (eg, US Pat. No. 4,990,283 (AUSIMMON SPA), February 5, 1991, US Pat. No. 5,498,680 (AUSIMTON S.P.A.) March 12, 1996 and U.S. Pat. No. 6,103,843 (AUSIMONT S.P.A.) August 15, 2000).

  The aqueous latex preferably comprises 20% to 30% by weight of at least one polymer (F).

  The aqueous latex may be up-concentrated by any technique known in the art.

  In step (i-2) of the second embodiment of the method of the present invention, composition (L) typically comprises at least one compound (M) of formula (I) and at least one compound. It can be obtained by adding to a composition comprising polymer (F), at least one filler (I) and medium (L).

  In step (i-2) of the second embodiment of the method of the present invention, composition (L) typically comprises at least one compound (M) of formula (I) and polymer (F). And 0.1 to 95% by weight, preferably 1 to 75% by weight, more preferably 5 to 55% by weight, based on the total weight of the compound (M).

The liquid composition [composition (L1)] obtained in step (iii-2) of the second embodiment of the method of the invention is advantageously
-Formula -Ym _-1 -AX _4-m (wherein X is a hydrocarbon group optionally containing one or more functional groups, m is an integer from 1 to 4, and A is A metal selected from the group consisting of Si, Ti and Zr, wherein Y is a hydrolyzable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group) Graft fluoropolymer [polymer (FG)], and-medium (L)
including.

  The polymer (FG) can be obtained in particular as outlined in FIG.

  In step (iii-2) of the second embodiment of the method of the present invention, the polymer (F) and the compound (M) of formula (I) are typically at a temperature comprised between 20 ° C and 100 ° C. React. A temperature of 20 ° C to 90 ° C, preferably 20 ° C to 50 ° C is preferred.

  A person skilled in the art appropriately selects the temperature according to the boiling point of the medium (L).

In step (iv-2) of the second embodiment of the method of the present invention, the liquid composition [composition (L2)] is advantageously hydrolyzable group Y and / or polymer (F) of compound (M). -G) at least partially hydrolysed and / or pendant groups of formula -Y _m-1 AX _{4-m where} X, A, Y and m have the same meaning as defined above. Which can be obtained by reacting by polycondensation, said composition (L2) being advantageously
At least one fluoropolymer hybrid organic / inorganic comprising, preferably consisting of a fluoropolymer domain consisting of chains obtainable by polymer (FG) and an inorganic domain consisting of residues obtainable by compound (M) Composite [polymer (F-H)], and-medium (L)
including.

  In particular, as schematically illustrated in FIG. 2, the polymer (FH) can be obtained with a fluoropolymer domain [domain (2)] and a compound (M) consisting of chains that can be obtained with the polymer (FG). It is understood that it comprises, preferably consists of inorganic domains [domain (1)] consisting of residues.

  The hydrolysis and / or polycondensation reaction is a second implementation of the method of the present invention, while at least some of the side functional groups of polymer (F) are reacted with at least some of the hydrolyzable groups Y of compound (M). While the reaction may be initiated during step (iii-2) of the form, the reaction is any of step (iv-2) to step (vii-2) of the second embodiment of the method of the invention. It is also understood that it may be continued between one.

  In step (iv-2) of the embodiment of the method of the present invention, the hydrolysis and / or polycondensation is usually carried out after heating at room temperature or a temperature of less than 100 ° C. The temperature is selected in consideration of the boiling point of the medium (L). A temperature of 20 ° C to 90 ° C, preferably 20 ° C to 50 ° C is preferred.

  As will be appreciated by those skilled in the art, hydrolysis / polycondensation usually produces low molecular weight by-products, which can be water or alcohols, depending on the nature of compound (M).

  The composition (L1) and / or the composition (L2) may further contain at least one acid catalyst.

  The selection of the acid catalyst is not particularly limited. The acid catalyst is typically selected from the group consisting of organic acids and inorganic acids.

  The acid catalyst is typically added to the composition (L1) or composition (L2) in an amount comprised between 0.1 wt% and 10 wt%, preferably between 0.1 wt% and 5 wt%.

  The acid catalyst is preferably selected from the group consisting of organic acids.

  Very good results have been obtained with formic acid.

  In step (iii-1) of the first embodiment of the method of the present invention, the composition (L) is generally deposited on the substrate (P) using techniques generally known in the art. Applied.

  In step (v-2) of the second embodiment of the method of the present invention, composition (L2) is generally deposited on substrate (P) using techniques generally known in the art. Applied.

  Non-limiting examples of suitable techniques include casting, doctor blade coating, metering rod (or Meyer rod) coating, slot die coating, knife over roll coating or “gap” coating, and the like.

  In step (iii-1) of the first embodiment of the method of the invention, the composition (L) is applied onto the substrate (P), preferably by a doctor blade coating technique.

  In step (v-2) of the second embodiment of the method of the present invention, the composition (L2) is preferably applied onto the substrate (P) by a doctor blade coating technique.

  In step (iv-1) or step (vi-2) of the method of the present invention, the substrate (P) is typically dried at a temperature comprised between 25 ° C and 200 ° C.

  Drying can be carried out in a controlled atmosphere, for example under an inert gas, typically excluding moisture (water vapor content below 0.001% v / v) or under vacuum It can be carried out.

  The drying temperature is selected so as to be removed by evaporation of the medium (L) from the substrate (P) obtained in step (iii-1) or step (v-2) of the method of the present invention.

  Curing, if any, is typically performed at a temperature comprised between 100 ° C and 250 ° C, preferably between 120 ° C and 200 ° C.

  In step (iv-1) or step (vi-2) of the process of the invention, depending on the nature of the medium (L) and the compound (M), in particular by hydrolysis and / or polycondensation which can be water or alcohol The low molecular weight by-product produced is possibly further accelerated by the combined action of heat and by-product removal, additional hydrolysis and / or polycondensation to provide step (iii-1) or step of the process of the present invention. It is at least partially removed from the substrate (P) obtained in any of (v-2).

  In step (v) of the method of the present invention, if any, the solid composite separator obtained in step (iv) is subjected to compression at a temperature typically comprised between 50 ° C and 300 ° C.

  The person skilled in the art chooses the temperature of step (v) of the process of the invention, taking into account, among other things, the melting point of the polymer (F) or polymer (F-H).

  In the event that any disclosure of patents, patent applications, and publications incorporated herein by reference contradicts the description of this application to the extent that the terms may be obscured, the description shall control.

  The present invention will now be described in greater detail in connection with the following examples, which are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Raw Material Polymer (F-1)-VDF / HFP / HEA Polymer Polymer (F-1) is a VDF polymer containing 0.7 mole% HEA and 2.3 mole% HFP.

Polymer (F-2)-VDF / HFP polymer Polymer (F-2) is a VDF polymer containing 15 wt% HFP.

Polymer (F-3)-VDF / HFP / HEA-silica hybrid composite The polymer (F-3) can be obtained according to the procedure as detailed in Example 2-A.

Base material (P-1)
Nonwoven fabric (commercially available from Hirose) made of polyethylene terephthalate of type 012TH-10 (H) having a thickness of 20 μm.

Compound (M-1)
Tetraethoxysilane (TEOS).

Filler (I-1)
Type S5505 silica (commercially available from Sigma Aldrich) having an average particle size of about 0.25 μm.

Determination of the thickness of the solid composite separator The thickness of the solid composite separator was determined according to the procedure of the ISO 4593 standard.

Determination of Dimensional Shrinkage of Solid Composite Separator The dimensional shrinkage of the solid composite separator was measured at room temperature by measuring the longitudinal dimension (D1) and lateral dimension (D2) at their respective selected temperatures (90 ° C, 120 ° C, 150 ° C). And 200 ° C.) for 1 hour in a ventilated oven.

Determination of Mixed Penetration Strength of Solid Composite Separator The mixed penetration strength of a solid composite separator is a hemisphere having a diameter equal to 3 mm according to the teaching of US Patent Application Publication No. 2007/0238017 (CELGARD LLC) Oct. 11, 2007. Determination was made at about 20 ° C. by pushing the nail with the tip through a separator test piece assembled between the positive and negative electrodes. The tip speed was 50 mm / min. The chip and the metal base in contact with the positive electrode were connected to an electrical circuit. As soon as a short circuit occurred due to a separator failure, electrical energy was supplied to the lamp to be lit. Mixed penetration strength is a measure of the force that must be applied to the tip to cause a short circuit through a separator specimen having a constant thickness by penetration of the electrode material.

Determination of tensile properties of solid composite separators Tensile tests were performed by testing specimens of V-type solid composite separators in accordance with the procedures of the ASTM D638 standard both in the machine direction (direction 1) and in the transverse direction (direction 2). . Because no extensometer was used, specimen shape correction was applied. Apparent elastic modulus was evaluated at a crosshead speed equal to 1 mm / min as the maximum slope in the initial zone of the stress-strain curve. A crosshead speed of 50 mm / min was used to evaluate other tensile properties.

Example 1-Production of Solid Composite Separator Example 1-A-Preparation of Liquid Composition Polymer (F-1) (0.20 g) is dissolved in 17.64 g of acetone at 55 ° C with stirring until complete dissolution. I let you. Then filler (I-1) (1.80 g) was added to it and the resulting solution was stirred at room temperature overnight. To it was added water [0.36 g] before coating, after which the resulting solution was gently stirred. The weight ratio of filler (I-1) to polymer (F-1) was 9: 1 and the weight ratio of acetone to water was 9.8: 0.2. The solid content thus obtained was 10% by weight.

Example 1-B-Coating and Pressurization of Liquid Composition A substrate (P-1) is placed on a support plate, and the solution obtained from Example 1-A is placed on the substrate (P-1). Was cast by a doctor blade at 5 mm / sec. The thickness of the wet layer was set to 85 μm. The liquid medium was removed at 60 ° C. for 15 minutes and then at 130 ° C. for 40 minutes. The separator so obtained was then pressurized at 130 ° C. for 10 minutes at 5 bar.

Example 2-Production of Solid Composite Separator Example 2-A-Preparation of Liquid Composition Polymer (F-1) (0.20 g) was dissolved in 17.43 g acetone until complete dissolution at 55 ° C under magnetic stirring. And dissolved. Then filler (I-1) (1.75 g) was added thereto and the resulting solution was stirred at room temperature overnight. Compound (M-1) (0.19 g) was added thereto and the resulting solution was homogenized for 10 minutes. Formic acid (0.08 g) and water (0.36 g) were added before coating and the resulting solution containing the polymer (F-1) silica hybrid composite [polymer (F-3)] was stirred gently. did. The weight ratio of filler (I-1) to polymer (F-1) was 8.7: 1. The weight ratio of polymer (F-3) to polymer (F-1) was 0.3: 1 and the weight ratio of acetone to water was 9.8: 0.2. The solid content of the solution thus obtained was 10% by weight.

Example 2-B-Coating and Pressurization of Liquid Composition The substrate (P-1) is placed on a support plate, and the solution obtained from Example 2-A is placed on the substrate (P-1). Was cast with a doctor knife at 5 mm / sec. The thickness of the wet layer was set to 85 μm. The liquid medium was removed at about 20 ° C. for 2 hours, 50 ° C. for 15 minutes, and then 150 ° C. for 40 minutes. The separator thus obtained was then pressed at 150 bar and 10 minutes at 5 bar.

Comparative Example 1:
The base material (P-1) was prepared as a solid separator.

Comparative Example 2:
The same procedure as detailed in Example 1 was followed except that polymer (F-2) was used.

Comparative Example 3:
Comparative Example 3-A—Preparation of Liquid Composition Polymer (F-1) (1.0 g) was dissolved in acetone (9 g) at 55 ° C. with magnetic stirring until complete dissolution. Then filler (I-1) (5.67 g) of silica was added to it and the resulting solution was stirred at room temperature overnight. The weight ratio of filler (I-1) to polymer (F-1) was 8.5: 1.5. The solid content of the solution thus obtained was 43% by weight.

Comparative Example 3-B-Coating of Liquid Composition The solution obtained from Comparative Example 3-A was cast on a support plate by a doctor blade system. The liquid medium was removed under vacuum at 130 ° C. for 6 hours.

  Table 1 below reports the dimensional shrinkage values of the separators obtained thereby.

  Table 2 below reports the values of the mixed penetration strength of the separators obtained by them.

  Table 3 below reports on the values of the tensile properties of the separators obtained thereby.

  Thus, a solid composite separator prepared by the method of the present invention by applying a liquid composition comprising polymer (F), filler (I) and optionally compound (M) onto substrate (P). Advantageously provides lower dimensional shrinkage values and higher mixed penetration strengths while maintaining excellent mechanical strength over a wide range of temperatures compared to prior art separators according to Comparative Example 1 and Comparative Example 2. I found out.

  In particular, the separator prepared according to Comparative Example 3 exhibited lower mechanical strength compared to the solid composite separator prepared by the method of the present invention while exhibiting low dimensional shrinkage values and high mixed penetration strength.

Example 3-Use of Solid Composite Separator in Secondary Battery The solid composite separator obtained in Example 1 contains a negative electrode containing graphite (TIMREX® SLP30) as an active material and LiCoO ₂ as an active material. A coin cell was prepared by placing between the positive electrode and the positive electrode. Both electrodes contain SOLEF® 5130 polyvinylidene fluoride as the binder and Super C65 as the conductive carbon black. The coin cell was filled with 150 μL of SELECTILYTE® LP30 electrolyte consisting of a 1M solution of lithium hexafluorophosphate (LiPF ₆ ) in ethylene carbonate / dimethyl carbonate (1: 1 weight ratio).

  A charge-discharge cycle test was performed, where the positive electrode and the negative electrode had a capacity ratio of 1. Table 4 below reports the cell discharge capacity values.

  Accordingly, it has been found that the solid composite separator according to the present invention is particularly suitable for use in electrochemical devices such as secondary batteries.

Claims (16)

A method for producing a solid composite separator comprising the following steps:
(I-1)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)],
-At least one inorganic filler [filler (I)], and-liquid medium [medium (L)].
Obtaining a liquid composition [composition (L)], preferably comprising them;
(Ii-1) obtaining a porous base material layer [base material (P)] made of one or more sets of polymer fibers;
(Iii-1) applying the composition (L) onto the substrate (P), thereby obtaining a wet substrate (P) [substrate (P-W)];
(Iv-1) drying the substrate (PW) obtained in step (iii-1) and then optionally curing to thereby obtain a solid composite separator;
(V-1) optionally, subjecting the solid composite separator obtained in step (iv-1) to compression. The following steps:
(I-2)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)],
-Formula (I):
X _4-m AY _m
Wherein X is a hydrocarbon group optionally containing one or more functional groups, m is an integer from 1 to 4, and A is selected from the group consisting of Si, Ti and Zr. And Y is a hydrolyzable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group)
At least one metal compound [compound (M)],
-At least one inorganic filler [filler (I)], and-liquid medium [medium (L)].
Obtaining a liquid composition [composition (L)], preferably comprising them;
(Ii-2) obtaining a porous base material layer [base material (P)] made of one or more sets of polymer fibers;
(Iii-2) reacting at least a part of the side functional group of the polymer (F) with at least a part of the hydrolyzable group Y of the compound (M), thereby forming one or more main chains. A main chain comprising repeating units derived from at least one fluorinated monomer, and a formula -Y _m-1 -AX _4-m (wherein X is a carbonization optionally comprising one or more functional groups) A hydrogen group, m is an integer of 1 to 4, A is a metal selected from the group consisting of Si, Ti and Zr, and Y is a group consisting of an alkoxy group, an acyloxy group and a hydroxyl group. A liquid composition [composition (L1)] comprising at least one grafted fluoropolymer [polymer (FG)] containing one or more pendant groups (which are hydrolyzable groups selected from Process and;
(Iv-2) Fluoropolymer domain consisting of chains that can be obtained by at least partial hydrolysis and / or polycondensation of the composition (L1) obtained in step (iii-2), thereby obtaining the polymer (FG) And a liquid composition comprising at least one fluoropolymer hybrid organic / inorganic composite [polymer (FH)] comprising, preferably consisting of, inorganic domains consisting of residues obtainable by compound (M) [ Obtaining a composition (L2)];
(V-2) The composition (L2) obtained in step (iv-2) is applied onto the substrate (P), whereby the wet substrate (P) [substrate (P-W)]. Obtaining
(Vi-2) drying the substrate (PW) obtained in step (v-2) and then optionally curing, thereby obtaining a solid composite separator;
(Vii-2) optionally, subjecting the solid composite separator obtained in step (vi-2) to compression. Polymer (F) comprises at least one fluorinated monomer [monomer (F)] and —O—R _x and —C (O) O—R _X groups, wherein R _X is a hydrogen atom, or at least 1 Obtained by polymerization of at least one hydrogenated monomer [monomer (H _f )] containing one or more functional groups selected from the group consisting of C ₁ -C ₅ hydrocarbon groups containing ₁ hydroxyl group) The method according to claim 1 or 2, which can be performed. Monomer (H _f ) is represented by formula (II):
Wherein each of R ₁ , R ₂ and R ₃ is equal to or different from each other and is independently a hydrogen atom or a C ₁ -C ₃ hydrocarbon group, and R _X is a hydrogen atom, or at least 1 C ₁ -C ₅ hydrocarbon moiety containing ₁ hydroxyl group)
The method according to claim 3, which is a (meth) acrylic monomer. Polymer (F) is
- a vinylidene fluoride (VDF), in _{-O-R x} and -C (O) _{O-R X} group (wherein, _{R X} is, _C 1 -C ₅ containing a hydrogen atom or at least one hydroxyl group, A polymer (F-1) comprising a repeating unit derived from at least one hydrogenated monomer [monomer (H _f )] containing one or more functional groups selected from the group consisting of hydrocarbon groups), And —O—R _x and —C (O) O—R _X groups, wherein R _X is a hydrogen atom or a C _{1 to} C ₅ hydrocarbon group containing at least one hydroxyl group. At least one hydrogenated monomer [monomer (H _f )] containing one or more functional groups selected from the group consisting of tetrafluoroethylene (TFE) and chlorotrifluoroethylene (CTFE) Polymer (F-2) comprising a repeating unit derived from a per (halo) fluoro monomer of a kind and at least one monomer (H) selected from ethylene, propylene and isobutylene
The method according to any one of claims 1 to 4, wherein the method is selected from the group consisting of:   In step (i-1), the composition (L) can be obtained by adding at least one filler (I) to an aqueous latex comprising at least one polymer (F). The method described.   In step (i-2), the composition (L) adds at least one filler (I) and at least one compound (M) to an aqueous latex containing at least one polymer (F). The method of claim 2, which can be obtained by:   The base material (P) is made of one or more sets of polymer fibers, and the polymer fibers are made of polyester such as polyethylene terephthalate, polyacrylonitrile, polyamide, polyimide, polyacrylate, polytetrafluoroethylene, and polyolefin. 8. The method according to any one of claims 1 to 7, wherein the method is made from an electrically non-conductive polymer selected from:   The method according to any one of claims 1 to 8, wherein the substrate (P) is a non-woven fabric made from one or more sets of polymer fibers.   The method according to claim 1, wherein the substrate (P) has a thickness comprised between 10 μm and 200 μm, preferably between 10 μm and 100 μm, more preferably between 15 μm and 50 μm. (1)
One or more main chains comprising a repeating unit derived from at least one fluorinated monomer [monomer (F)], and —O—R _x and —C (O) O—R _X At least one side functional group selected from the group consisting of a group wherein R _X is a hydrogen atom or a C ₁ -C ₅ hydrocarbon group containing at least one hydroxyl group, One fluoropolymer [polymer (F)], and at least one inorganic filler [filler (I)]
At least one layer [layer (1)] made from a solid composition [composition (S)] comprising: and adhered to at least one surface of said layer (1),
(2) A solid composite separator including a porous base material layer [base material (P)] [layer (2)] made of one or more sets of polymer fibers.   The solid composite separator according to claim 11, which can be obtained by the method according to claim 1.   Layer (L1) comprises at least one fluoropolymer domain, preferably composed of a fluoropolymer domain consisting of chains obtainable by polymer (FG) and an inorganic domain consisting of residues obtainable by compound (M). 13. Solid composite separator according to claim 11 or 12, made from a composition (S) further comprising an oropolymer hybrid organic / inorganic composite [polymer (F-H)].   The solid composite separator according to claim 13, which can be obtained by the method according to claim 2.   Use of the solid composite separator according to any one of claims 11 to 14 in an electrochemical device.   The use according to claim 15, wherein the electrochemical device is a secondary battery.